Results 21 to 30 of about 972 (166)
Detection of Pipeline Deformation Induced by Frost Heave Using OFDR Technology
Frontiers in Physics, 2021 Oil and gas pipelines are critical structures. For pipelines in the seasonal frozen soil area, frost heave of the ground will result in deformation of the pipeline. If the deformation continually increases, it will seriously threaten the pipeline safety.
Tao Jiang +4 more
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Geomatics, Natural Hazards & Risk, 2021 Internal thrust force of unstable rock and soil mass is an essential parameter for prediction of many geological hazard. Currently, fiber bragg grating (FBG) and optical time-domain reflectometer (OTDR) are widely used to measure internal stress of ...
Pu Wang, Yimin Liu
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OFDR analysis of Si photonics FMCW LiDAR chip
Optics Express, 2023 We experimentally analyzed the internal reflection and loss of each component in a Si photonics frequency-modulated continuous-wave light detection and ranging (FMCW LiDAR) device using optical frequency domain reflectometry (OFDR) with a spatial resolution of better than 2.5 µm.
Mikiya Kamata, Toshihiko Baba
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High resolution DAS via sinusoidal frequency scan OFDR (SFS-OFDR)
Optics Express, 2015 There are many advantages to using direct frequency modulation for OFDR based DAS. However, achieving sufficiently linear scan via direct frequency modulation is challenging and poses limits on the scan parameters. A novel method for analyzing sinusoidal frequency modulated light is presented and demonstrated for both static and dynamic sensing.
Eyal, Leviatan, Avishay, Eyal
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Distributed Optical Fiber Sensors Based on Optical Frequency Domain Reflectometry: A review
Sensors, 2018 Distributed optical fiber sensors (DOFS) offer unprecedented features, the most unique one of which is the ability of monitoring variations of the physical and chemical parameters with spatial continuity along the fiber.
Zhenyang Ding +7 more
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Nihon Kikai Gakkai ronbunshu, 2020 In the concept of the disposal of High Level radioactive Waste (HLW) in Japan, bentonite material such as the engineered barrier system is planned to backfill around over-pack in the disposal tunnel.
Masao UYAMA, Toshihiro SAKAKI
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IEEE Photonics Journal, 2021 The phase induced intensity noise (PIIN) may seriously reduce the signal-to-noise ratio (SNR) of continuous-wave coherent Doppler lidar (CW-CDL), thereby limiting its performance in practical applications.
Zheng Tang +7 more
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Random Fiber Grating Characterization Based on OFDR and Transfer Matrix Method [PDF]
Sensors, 2020 Random fiber gratings (RFGs) have shown great potential applications in fiber sensing and random fiber lasers. However, a quantitative relationship between the degree of randomness of the RFG and its spectral response has never been analyzed. In this paper, two RFGs with different degrees of randomness are first characterized experimentally by optical ...
Zichao Zhou +5 more
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Quasi-distributed vibration sensing using OFDR and weak reflectors [PDF]
Optics Letters, 2019 We proposed a quasi-distributed vibration sensing technique using in-line weak reflectors and optical frequency domain reflectometry (OFDR). As a result, we achieved an 8 kHz measurable vibration frequency with a 15-20 cm spatial resolution employing a low repetition rate (∼8 Hz).
Mengshi Zhu +3 more
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Performance of a solid-state frequency-shifted feedback laser in optical ranging [PDF]
Journal of the European Optical Society-Rapid Publications, 2009 The performance of a frequency-shifted feedback laser (FSFL) using a Nd:YVO4 crystal as gain medium was investigated as light source in high accuracy optical ranging based on optical-frequency domain reflectometry (OFDR).
Ndiaye Cheikh +2 more
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